Direction signal



Nov. 5, 1929'. G. MaCKAY 1,734,094

DIRECTION SIGNAL Filed Jan. 50, 1928 2 Sheets-Sheet l WMA/rae faef Min/74% Nov. 5, 1929. v G, MaoKAY 1,734,094

DIRECTION SIGNAL Fil'ed Jan. 50, 1928' 2 Sheets-Sheet 2 VMM 2"?.

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Patented Nov. 5, 1929 UNITE STATES GEORGE MACKAY, OF LOS ANGELES, CALXFORNIA DIRECTON SIGNAL Application led January 30, 1928.

My invention relates to direction signals for automobiles, and it has for a purpose the utilization of the vacuum produced at the intake manifold of the vehicles engine for actu- U' ating the semaphore arm of the signal to seengine, such principle being adaptable to vacuum-operated windshield wipers or any other device depending upon vacuum for operation.

l will describe only one form of direction signal of automobiles embodying my invention and will then point out the novel fea tures in claims.

Fig. 1 is a fragmentary view showing in phantom perspective an automobile having applied thereto one form of direction signal embodying my invention;

Fig. 2 is an enlarged view showing in side elevation and partly in section the semaphore arm, support, and operating mechanism therefor and of a signal shown in Fig. l;

Figs. 3 and t are sectional views taken on the lines 3 3 and 4 4, respectively, of Fig. 2;

F 5 is a View taken on the line 5 5 of Fig. 8;

Fig. 6 is an enlarged longitudinal sectional view of the control valve in the signal shown in Fig. 1;

Fig. 7 is a detail perspective view of the valve shown in Fig. 6;

Fig. 8 is a View taken on the line 8 8 of Fig. 6;

Fig. 9 is a sectional view taken on the line 9 9 of Fig G;

Fig. 10 is a phantom view of the automobile engine and showing a vacuum storage tanlr associated therewith and embodying my invention; and

11 is an enlarged sectional view taken on the line 11 11 of Fig. 10.

Serial No. 250,551.

Similar reference characters refer to similar parts in each of the several views.

Referring specifically t-o the drawings, and particularly Figs. 1 and 2, my invention in its present en'ibodiment comprises a semaphore arm A shaped to simulate the outline of the human hand, and preferably hollow, with glass panels 15 to permit illumination thereof at night by means of an electric lamp 16. This semaphore arm is movable about a horizontal axis 'to occupy the usual signalling positions, namely Right, Left, and Stop, and a non-signalling position in which it is concealed within a housing H. As shown in FigL 3 the housing H is secured to a frame F provided with an extension 17 constituting a bracket adapted to be secured to the car body, preferably adjacent or on the left front body post, as illustrated in Fig. 1, so as t-o be within view of the operator of the vehicle.

As best shown in 3, the semaphore arm A is fixed at its upper end to a stub shaft S formed of insulating material and provided with a socket in which the plug of the lamp 16 is adapted to seat. The lamp 15 is of the single contact type and is hence provided with a Contact 18 extending into a conducting sleeve 19 to which latter is fixed a contact plate 2O disposed within a pocket 21 of the frame F with the latter closed by a cover plate 22. In Fig. 5 the cover plate 22 is removed to reveal the construction of the Contact plate 20. As shown, the contact plate is provided with a notch 20L iof such area to freely receive therein a stationary Contact 23 connected to a wire 24. This contact 23 constitutes one terminal of a circuit (not shown) including a source of current such. as a battery (not shown), while a spring-pressed contact 25 provides the other terminal of the circuit and, as shown in Fi 3, is in electrical Contact with the plug of the lamp 16 and the frame F. The frame is formed of conducting material and is grounded to complete a circuit through the grounded side of the source of current as will be understood. The purpose of the notch Q0 in accommodating the stationary contact 23 is to disrupt the lamp circuit when the arm A is in non-signalling position, and will thus be understood that the lamp 16 is Cil illuminated only when the semaphore arm is in one of its signalling positions.

rlhe frame F is made up ot two sections 25 and 27 suitably secured to each other and having their confronting sides constructed to form a pocket 28 (Figs. 3 and 4l) in which rotates a gear 2S). This gear projects through a slot 30 in a cylinder 3l and constantly meshes with a rack bar secured to a piston l?. This piston is movable in the cylinder 3l and comprises a rod to which the rack ba r is suitably fixed and at the ends ot which are heads 3l and 35. rThe cylinder 3l is accommodated by the sections QG and Q7 of the trame and is completely housed tnereby as will be clear :trom an inspection ot' Fig. fl.

The piston l) is adapted to be pneun'iatically reciprocated in the cylinder 3l to impart a corresponding movement to the rack bar 32 and thereby actuate the gear if) to move the arm A to any one of its several signalling positions and to return the arm to nonsignalling posit-ion. Although l am employing air to actuate the piston ll am dealing with negative pressures in order that l may utilize. the vacuum producerl at the intake side oft the automobile engine. 'lo conduct or transmit the negative pressr-.re or vacuum oi the motor to the cylinder Sil to produce downward movement ot the piston l? and to the various required degrees 'for causing the semal'ihore arm to assume its various signalling positions, l provide. tubes o6, 3T, and 88 connected, respectively, at one end to ports 3h, 3T, and 38 in the cylinder 3l below the normal uppermost positions ot the piston l?. its shown in 2, these ports hf, 3T", and 3S are arranged one above the other in order to progressively reduce the pressine olI air at the lower side oil the piston and thereby delinitely coi'itrol its dovmward movement. in lin'oceeding down 'ardly the piston head functions to progressively close the ports so that alter the piston has reached any one oit its three positions Alurliher reduction in air pressure will cease and the piston, as a conseipience, will be maintained in this predetermined position so as to hold the semaphore arm in a corresponding position. The opposite ends ot the tubes are connected, respectively, to pipe elbows 36, b, and 58 which7 as shown in Fig. (Si are threaded in suitable openings in a cylindrical body 39. This body 3i) is adapted to be secured to any suitable part olf the automobile, pretferably on the steering post, as illustrated in Fig. l7 so as to be in convenient reach ot the operator ot the vehicle. As shown in Fig. the body 239 is provided with a tapered bore in which is rotatable a coi'respondingly shaped valve V. @ne end ot the valve is formed with a lip Ll0 which abats one nid ot the body 53S), the opposite end el the valve having secured 'thereto a plate body 3l). The valve is hollow to provide a chamber lo and slotted to term an elongated port l? which is in constant communication with a pipe elbow #1:8 tl beaded in the body 2&9. The elbow is connected to one end otl a tube -l which extends trom the body 39 dowinvardly lo a pipe 5() projecting through the dash-board of the automobile and extending into the top ot a closed tanlr 5l. rlldjacent the bottom oit' the tank 5l a pipe 52 is connected thereto9 and in the vertical portion ol this pipe is a plug havinga port "il therein with the upper end et die plu corcaif'ed to provide a seat for a ball vali"- o. ily means ot a spring 56 the valve is yieldably urged to closed position with. respect to the port -l. 'lhe opposite end of the pipe 52 is connected to the usual pipe line employed tor connecting the gasoline 'num tank 5S to an inta-lie manifold 59 ie engine G0.

l'ly connecting the tank 51 to the intake maniifold, as above described, the suction created in the manifold when the engiiie operated produces a partial vacuum in the pipe and, when this vacuum is built up to a 'degree suilioient to overcome the tension olf the spring 56 and the weight oi' the ball the valve opens, thus placing the tant; 5l 'in connnnnication with the intake maniiiold. ily providing the tant'L an enclosed chamber oil' relatively large area is formed in which a relatively high degree of vacuum can be ilformed and thereby providing a snpply of vacuum which is adapted to be utilized to compensate ior any inadequacy in respect to the vacuum-preducing property ot the engine. The exact manner in which this storage tank ilfnnctions will be more fully set torth when describing the oneration of the signal.

lhrough the medium oit the pipe 5l), tube and the elbow the vacuum produced, above described, is transmitted to the valve chainber lli and :troni the latter to the dillicrent tubes Sli, 3?, and 3S by the provision oi' ports (il, (327 and (l-3. lhe ports (ll (nl, and (lil are positioned as illustrated in Fig. Y in order that they may be brought into registration with the pipes Se", 3T", and 2381), respectively` and in diliferent positions oit the valve V.

To insure proper operation of the piston P in moving the semaphore arm to its signalling positions and returning it to non-signalling position, itis necessary that air at atmospheric with an elbow pipe 67 threaded in the valve.

body 39, as shown in Fig. 6, and with which a valve port 68 and a valve groove 66 are adapted to separately register. The groove n 69 extends longitudinally of the valve V and is so positioned that when in registration with the pipe 67 it places a ventport 70 of the valve body in communication with the pipe iii so that air from atmosphere can pass into the pipe and from the later through the tube 66, conduit 64 and into the cylinder through the port 65 to the upper side of the piston P. By this admission of air at atmospheric pressure it may be said that the vacuum created at the lower side of the piston is permitted to properly act in moving the piston downwardly but in reality the negative pressure produced by the vacuum 'at the lower side of the piston merely permits the air admitted to the upper side of the piston to force the piston downwardly.

In returning` the piston P to its uppermost position, it is likewise necessary to produce a vacuum at the upper side of the piston and a positive pressure at the lower side. By moving the valve V to a position in which the port 68 registers with the pipe 67 the valve chamber 46 is thus placed in communication with the pipe 67 so that the negative pressure produced by the motor is transmitted from the port 47 through the chamber 46 and port 68 to the pipe 67, and thence to the upper side of the piston P through the conduit 64. With the valve V in this position a circumferential groove 7l in the periphery of the valve is brought into registration with the pipe 38h and a vent port 72, all as clearly shown in Fig. 9. As the pipe 38b is connected to the tube 38 air from atmosphere can now pass 'through the port 72, groove 71, pipe 381, tube 38, and port 38a into 1the cylinder at the lower side of the piston P. As this admission of air occurs simultaneously with the withdrawal of air from the upper side of the piston, it will be manifest that the piston P is, as a result, moved upwardly to its normal position.

In practice, the operator of the vehicle can, by a manipulation of the handle 44, move the valve V to any of its several positions to place any port or groove in communication with the respective elbow pipes so as to transmit positive or negative air pressures to either side of the piston P and thereby move the semaphore arm A to or from any of the signalling positions, the lamp 16 being illuminated when the arm is in any one of its signalling positions so as to render it visible at night.

In actual practice, the vacuum produced by the engine 60 does not remain constant by reason of the variation in speed of the engine.

vAs the engine speed varies inversely with the load when the automobile is ascending a hill the engine speed decreases and frequently to such a degree that the suction produced at the intake side of the engine is insufficient to create adequate vacuum for operation of the signal. However, by the provision of the storage tank 5l such a defect is eliminated. lVith the engine operating at the normal speed, sufficient suction is produced in the pipe 52 to retain the valve 55 in open position thus withdrawing air from the tank 5l, and thereby creating in the tank a relatively high degree of negative pressure or vacuum. As long as the negative pressures at the intake manifold and within the tank 51 are the same or the negative pressure at the manifold greater than that in the tank, the valve 55 will remain open. However, as soon as the ne Oative pressure at the manifold drops below the pressure in the tank 5l, the valve 55 closes so that the tank is no longer in communication with the manifold. This naturally prevents loss of negative pressure in the tank back through the manifold and, consequently, the vacuum supply is retained. This supply is sufficient to insure operation of the signal for a period sufficient to span any ordinary interval in which the suction produced at the manifold is subnormal as a consequence of the temporary reduction in speed of the engine. It will, of course, be understood that as soon as the normal speed of the engine is restored and with it the corresponding increase in suction produced, the valve 55 will be opened to again place the tank 5l in communication with the manifold 59. This vacuum storage principle is likewise applicable to a windshield wiper of the vacuum-operated type to insure continued oscillation of the wiping element particularly when the automobile is ascending the hill.

Although I have herein shown and described only one form of direction signal embodying my invention, it is to be understood that various changes and modifications may be made herein without departing from the spirit of the invention and the spirit and scope of the appended claim.

I claim:

In a direction signal, a semaphore, a cylinder, a piston operatively connected to the semaphore and movable in the cylinder to cause the semaphore to occupy any one of several signalling positions, vacuum-producing means for actuating the piston having a plurality of connections with the cylinder at different points and at opposite sides of the Cil pistou to effeetdil'erent degrees of movement of the pieton in either direction, means admitting air at atmospheric pressure to that side of the piston opposite the side at which the vacuum is produced, and a valve for oontrolling both of said means and having a easing and a valve body provided with ports so positioned therein and in respect to each other that by manipulation of the Valve body the vaeuunii-producing means is connected to one side or the other of the piston While the means for admitting air to the Cylinder Vis connected to the opposite side of the piston.

Signed at Los Angeles in the county of Los Angeles and State of California this ninth day oi January, 1928.

GEORGE MACKAY. 

